Rare earthworm found in Somerset

A rare earthworm has been found by earthworm recorder Ben Crabb in North Somerset.  Microscolex phosphoreus is a species of earthworm thought to originate from South America that is previously known from gardens and golf courses.

Microscolex phosphoreus is an endogeic (shallow-burrowing) species of earthworm belonging to the family Acanthodrilidae. It is the only species of this family found in the UK, and as such it is believed that this species may have originated from South America. It has been previously reported from areas of high organic content (such as compost heaps) and golf courses. The specimen was sent to the Natural History Museum (London), where it was verified by Emma Sherlock. Ben supplied the following information and photo for us to share.

I found the worm on 2nd June 2019 in the back garden of a house on the edge of Nailsea, a small town in North Somerset. I had pulled up a weed which was growing in the cracks between flagstones in the patio. I noticed that there was a tiny worm amongst the roots of the weed. The worm was so small that my first thought was that it could be Dendrobaena pygmaea but the microhabitat seemed wrong for that species. I was very surprised when I looked at it under the microscope and saw that the clitellum started at segment 13. The worm measured approximately 18 mm long and was approximately 1.1 mm wide at the widest part of the clitellum. I found the worm in daylight and there was no sign of any phosphorescence. I suspect there must be a population of the species in the garden but I haven't found any more, although I haven't searched for them particularly hard. I have heard that the species' stronghold in this country is the greens of golf courses. Perhaps this is the first time it has been found in a patio!

Microscolex phosphoreus

It is only the third record of this species submitted to the National Earthworm Recording Scheme. The previous records were:

  1. 2006 record of Microscolex phosphoreus from a research paper by Trevor Piearce. The worm was found in a woodland that was previously a landfill site in Cheshire.
  2. 2016 record of Microscolex phosphoreus from earthworm recorder Keith Lugg. The worm was found in the garden of a holiday cottage in North Devon.